Rosario to Demi-Fiend
by BlackTyrantValvatorez
Summary: The Demi-Fiend is scouting the universe for any and all enemies of the Great Will when he transfers to Youkai Academy. Seeing Tsukune Aono, Moka Akashiya, and others as potential allies, he decides to befriends them and goes through their wacky hi-jinks. Demi-Fiend x Harem, Tsukune x Kurumu. Follows Shin Megami Tensei: Nocturne's True Demon Ending.
1. Chapter 1

A black-painted jeep drove alongside a bus that was heading somewhere. The bus stopped to pick up a boy, but the jeep kept moving, its occupants kept hidden from view by the windows. The jeep eventually entered a long tunnel and it was soon followed by the bus. The jeep stopped at a scarecrow-bus stop long enough for one of its doors to open and allow a black-haired fifteen-year old wearing a pair of black pants, a pair of black shoes, and a hooded jacket that had long sleeves along with a pair of black gloves to exit before speeding off. The bus then stopped and allowed Tsukune Aono to get off before it also drove away.

Tsukune noticed the boy in the hooded jacket and saw that he had the hood raised over his head so that it was covered and asked, "Who are you?"

"I am Naoki Kashima. You must be the one the humans call Aono Tsukune." the black-clad boy replied.

"What? How could you figure out my name?" Tsukune asked as the two of them walked toward the school in the vicinity.

"You might already suspect it, but I am actually not human. I was dropped off here by a friend of mine. I myself happen to be the champion of that friend." Naoki said before he heard a bicycle coming near and immediately rolled to avoid being hit by a bike. Tsukune was not so lucky as his blazer got snagged by one of the bike's gears and both it and its rider flipped over him as he got blindsided and forced to tumble along before crashing into a tree. Naoki immediately got to Tsukune and got the bike off of him before setting it down somewhere else and taking off. Tsukune's eyes opened and he noticed that he was laying on his back and had his left hand reach out and touch solid ground to support himself and managed to get to a sitting position. The instant his right hand was moved as to reach ground so that he could get up, he felt someone's skin instead of the ground. He turned his head and saw a pink-haired girl who had a rosary on her neck, which was the only change on her uniform. Tsukune saw that his right hand was touching the girl's left leg near her skirt.

The girl's face blushed profusely before she said, "Sorry about that."

Tsukune was unsure of what to say and asked, "Who are you? I am Aono Tsukune."

"Akashiya Moka. It's nice to meet you, Tsukune." the girl replied before Naoki interrupted with a "Hey." and the two of them got up and went towards the school, Moka on her bike and Tsukune on foot.

* * *

After the opening ceremony, Tsukune went to Year One's class 3 while Naoki went to Year Two's class 3. In class 1-3, Tsukune looked from his seat as a woman with blonde hair walked in. She went to her stand and introduced herself.

She said, "Hello everyone and welcome to Youkai Academy! I am your homeroom teacher, Shizuka Nekonome. As all of you know, this school is a place for Youkai. Humans control most of the Earth, so in order for Youkai to survive, we must learn to co-exist with them. That's the point of our school. In fact, it's a rule that you should not let other students know about your true form.

A student with muscular green skin asked, "Heeh Teech, wooldn't it be eaziya tuh eet teh stoopid humans? And with teh pretteh gurlz, molezt dem?"

"Well," Shizuka Nekonome said, "Here at Youkai Academy, everyone is a monster; there are no real human around. This place is protected by a barrier and keeps the humans out because non-Youkai that directly touch the barrier die instantly. And who knows what would happen if a human was able to get past?"

Sudden the door to the classroom opened and Moka came in. "Sorry I'm late." she said.

Once class broke for lunch, Tsukune took off both to find a vending machine and explore the school. He noticed that Moka was stalking him as was another person. That person said to Moka, "You're Moka Akashiya right? My name's Komiya Saizou. What do you think you're doing anyway, stalking that weakling!?"

Moka turned around to answer Saizou, but when she did Tsukune used the opportunity to get away from them and it was only when Saizou asked Tsukune to say something and hear nothing that both of them realized that Aono had bailed.

"Well, this ended for nothing. Guess I'll sell him later." Saizou said before leaving, looking rather pissed.

Tsukune got a bottle of water a vending machine on the roof and drank it, noting that there was nothing unusual about it. After school was over for the day he decided to check out the dorm, but when he did, Saizou saw him and called to Aono, "Hey you, over here!"

Tsukune turned to Saizou and got closer to him. "I saw you being stalked by Moka earlier. Some other chick with violet hair was also checking you out, but the point is that there's a rumor going around that the principal secretly enrolled a human into Youkai Academy and I'm looking for suspicious people. Seen anyone out of the ordinary?" Saizou asked.

"Well, aside from a green-skinned guy in my class and Naoki Kashima, I haven't seen anyone weird yet." Tsukune replied.

"That's a good answer. Anyways, don't try any funny stuff with Moka or I'll kick your ass!" Saizou said before leaving.

After looking around the his dorm room and finding a Preta guarding Naoki's room, Tsukune overheard a commotion and went towards it. At the scarecrow-bus stop, Moka was standing still while Saizou and the muscular green-skin were fighting nearby.

"Grr, you're a tough bastard!" Saizou said to the green-skin.

"Dis feel real good! Orks alwehyz crehvin' fer fight!"

"Heh, so you're an 'Ork,' eh. Well, just so you know, I'm an 'Orc,' you stupid green-skin!" Saizou said before transforming into his monster form.

The two of them fought each other for a while before Saizou returned to normal form out of exhaustion. He was then knocked down and pummeled by the Ork who declared, "Heer mah nayme 'n feer it, dum butz! I am teh Ork da boyz call Smashfizt! Now git yer buggin' zelf awehy or I start a 'WAAAGH' theht will follow yer deeth!"

As Saizou ran away screaming like a frightened little girl, Smashfizt tried to grab Moka, but the Ork had a block of ice form on him that broke, injuring the green-skin. Tsukune saw Naoki rush forward along with a Mizuchi.

Smashfizt got up and said to Naoki, "Yer tuff fer a weirdboy, ain't ya?"

"You provoked me. Now it's your time to get thrashed." Naoki said before taking his gloves and jacket off, revealing what looked like tattoos that had a green tint running across the guy's body.

Naoki's skin darkened as he said, "Xeros Beat." and he did a roundhouse kick and blue projectiles hit Smashfizt and binded the Ork before the Mizuchi uttered, "BUFUDYNE." and once again a block of ice formed around Smashfizt and broke. Not taking any chances, Naoki punched the Ork and caused him to cough up a few spores before he ran away into the surrounding area. Naoki then dismissed the Mizuchi, who disappeared before a pair of Will-o-wisps popped up and attacked. Naoki unleashed a Xeros Beat that killed the demons, but then a Girimehkala appeared along with two Shikigami.

"Under the terms of our contract, I call you forth. Dionysus!" Naoki said as he summoned the Greek god of wine and he unleashed a Fire-boosted Agidyne on the Girimehkala. Naoki quickly summoned the insane monk Daisoujou and then the Girimehkala tried to hit Naoki, but missed and then a Shikigami unleashed a small Zio spell on Moka, who got slightly hurt by the electrical attack. Dionysus unleashed another Agidyne on the Girimehkala, killing it as Daisoujou used a Preach that killed the Shikigami, but then six Phantoms and a Surt appeared.

It was at this point that Tsukune pulled the rosary off of Moka and a pink light surrounded her for a few seconds. Once it died down, the vampire was hardly recognizable by Tsukune. Moka's hair had turned silver from its pink color, her breasts that were ordinarily at a C-cup had increased to a healthy D-cup and her ass grew slightly. Moka was also no longer timid and held herself high.

"Know your place!" Moka yelled as she brutally attacked the Surt with various kicks and finished with a kick to the head that seriously hurt the fire giant. Naoki noticed and unleashed a Xeros Beat that killed it along with four of the Phantoms and injuring the remaining two. Daisoujou Meditated one of them to death while Dionysus finished off the other with a Life Drain.

"Hmm, you're pretty tough." Moka said to Naoki as he dismissed his fellow demons.

When Tsukune returned the rosary to Moka, she returned to normal. "Knowing you, Tsukune, you're probably not human. I smell the scent of a dragon from you." Naoki said.

"W- What!?" he said as him mind felt something within him weaken.

* * *

Naoki's Magatama in this chapter: Marogareh

Skills set on Marogareh:

Xeros Beat

Pierce

Wild Dance

Javelin Rain

Oni-Kagura

Spiral Viper

Focus

Lunge

Normal Resistance

**A/N: Yeah, Naoki Kashima is a full-blown Demon. He's scouting out the Rosario + Vampire Universe for anyone that might ally themselves with the Great Will and if he finds anyone who is an ally of the Great Will, that person has to die. So far right now, Moka and Tsukune are potential allies.**


	2. Chapter 2

**A/N: Alright, some things to clear up:**

**1. Naoki is serving Lucifer as his champion.**

**2. His Magatamas have been enhanced so that they can store any skills for any situation, but only eight of those skills can be used at any time.**

**3. He isn't using Masakados right now because Fairy Tale hasn't shown up yet.**

**3. Naoki's Magatamas are equipped by him to handle whatever situation is in the chapter, so here, Demi-Fiend has Iyomante set so that he is unaffected by Kurumu's charms.**

**All that aside, enjoy!**

* * *

Tsukune was on his way to classes after having breakfast with Naoki Kashima. As they looked for Moka, the two of them heard a gasp and a moan. Naoki's instincts took over and he uttered, "Succubus. Be aware of your surroundings. They are masters of Mind attacks and especially like to charm men. I have some Dis-Charms on me in case you get afflicted, but they are limited in supply. In any case, I currently have Iyomante set so I'm immune to illusions and charms of any kind." The two of them heard the Succubus say, "S-someone. . ." and decided to at least find out who she is.

When they found the Succubus, Naoki knew that this one was different from the one that was in his Demon Compendium. Instead of having blonde hair and wearing a black one-piece, this Succubus wore a sweater over the academy's blouse and had blue hair. Another thing was that the Succubus had large E-cup breasts instead of the modest B-cup chest size that the compendium-summoned Succubi had.

The Succubus said, "Help me, please. . . Lend me a hand. I- I'm feeling ill right now."

Tsukune approached cautiously, but when he did, the Succubus got up and used a Sexy Gaze on him, charming him. Naoki immediately used a Dis-Charm on Tsukune and then the Succubus tried to use a Sexy Gaze on Kashima, but the word 'VOID' appeared over his head. Thinking fast, the Succubus grabbed Tsukune and ran to the infirmary with Naoki in hot pursuit.

After managing to shake off Naoki temporarily, Tsukune was lying on a bed in Youkai Academy's infirmary while the Succubus was straddling him. She introduced herself as Kurumu Kurono. She tried to kiss him, but before she could do so, Tsukune felt the charm wear off and said, "Hold on, things are just going too fast between us right now." and then Kurumu felt betrayed. She grew large bat-like wings from her back and a tail sprung out of her body.

"Grr, I'm pissed!" the Succubus said before Naoki grabbed her and threw her out a window as her nails lengthened into claws.

A few minutes later, Tsukune was watching Naoki and Kurumu fight each other in the woods from a reasonable distance. Kurumu had quickly realized from earlier that Naoki was immune to Mind attacks and so opted to use normal strikes with her claws as Naoki dodged her attacks like a pro. The instant Naoki could attack, he immediately made an Evil Gaze at Kurumu that weakened her and then summoned a Koppa after using Beast Eye. The Koppa then proceeded to bind Kurumu with a Shibaboo spell.

Very quickly, Moka came and noticed the bound Kurumu and tried to hurt her, but Tsukune was able to talk her out of it since at the moment, Kurumu would die if she was physically harmed any further. Immediately four Incubi and a Nue appeared. The Nue tried to hit Tsukune with a Mudo attack, but he got out of the way quickly as an Incubus tried to use a Life Drain on Naoki, but the Demi-Fiend dodged it. Another Incubus was only slightly more successful, failing to charm Moka with a Marin Karin spell and another tried to attack, but missed. Naoki Kashima immediately used a Diarahan on Kurumu, who thanked him by killing an Incubus with a claw strike and maiming another at the same time. Tsukune pulled the rosary off of Moka and after transforming killed the remaining Incubi and killed the Nue with a kick to the head, only for two Girimehkalas and a Nyx to appear.

Moka tried to kick one of the Girimehkalas, but she ended up seriously injuring herself since the one-eyed elephants repel Physical attacks. The Girimehkala that Moka tried to kick tried to unleash a Panic Voice, but was interrupted by a Megidola from Naoki. Then the Nyx failed to lull anybody to sleep with Dormina, failing to hit Tsukune, Moka, and Kurumu while Naoki flat-out had the familiar 'VOID' message appear over his head and then the Demi-Fiend used another Megidola to destroy the unwelcome guests.

* * *

Naoki's Magatama in this chapter: Iyomante:

Skills set on Iyomante:

Beast Eye (hacked on)

Void Curse

Void Nerve

Evil Gaze

Phys Repel

Megidola

Diarahan

Mana Aid

Immune to Mind

**Update: Yeah, sorry about that. I don't really care if I get reviews or not though, and sometimes a person whose questions I want to answer doesn't allow PMs.**


	3. Chapter 3

Soon after becoming friends with Kurumu, it was time to study for 1st semester mid-term exams. It took around two weeks due to the constant demon attacks that forced the faculty plus Naoki Kashima to constantly remain on guard. After exams were finished, the first-years were trying to get a good look at their results. Tsukune had managed to get 20th place while Moka was at 6th and Kurumu was in 18th place. Naoki was in the top five for the scores of the second-year students. One guy said, "Hey check it out! Moka-san's got the 6th spot!" Another guy said, "No way! She must be smarter than she looks!"

While Moka was getting a ton of attention from the male students, one young girl in a cape and hat was looking at her before noticing the Demi-Fiend behind her and turned around to look at him. "Congratulations, Sendo Yukari." he said, clapping his hands slowly. "You managed to get the number one spot in the first-years. I won't reveal my score, but I am in the top five for the second-year students. Oh yeah, the name's Naoki Kashima. Kodama, come see your new playmate." he called before summoning the demon.

Kodama looked at Yukari and said, "You friend?"

The witch looked at the Kodama and said, "Sure, I'll be your friend."

"Yay, Jirae Kodama made friend."

At lunch break, a Djinn had accidentally caused a bit of trouble by unintentionally burning down a bathroom stall in the men's room when it went there to take a dump after eating a really spicy pepper that Saizou had sneaked into the Djinn's lunch as a prank. While Tsukune was eating with Kurumu and Moka, Yukari was considering doing something to make Moka go away only to get interrupted by a Girimehkala that had crashed in. It did not notice the witch and instead attacked anything close to it, which included the cafeteria staff. It was quickly subdued once a student who moved extremely fast arrived and it took only two Bufudynes before a third one killed it.

Quite a while later after school was over for the day, club talk was in the air and Naoki was able to start a 'Demon Club' and appointed a compendium-summoned Ose as the President of the club. Tsukune and Kurumu decided to join the Demon Club as did Yukari and Moka. A Pyro Jack that had been called from Naoki's demon compendium was given the role of treasurer while oddly enough, Saizou joined as the Public Safety Representative and Tsukune was put in charge of communicating with the Newspaper Club and Principal. While talking with the student from the cafeteria that had dealt with the Girimehkala, Tsukune was able to learn his name, Gin, and that Gin was a Werewolf whose main ability was speed. Gin also turned out to be able to use Ice magic masterfully as he demonstrated with a Bufula on a Kaso that had crawled in and was the only member of the newspaper club.

While that was going on, the Public Safety Commission was preparing to do something. Kuyo, the leader, had learned of the Demon Club that Naoki Kashima started and made plans to check it out at a later date. In the meantime, in a wooded area near the school, six Shiki-Oujis and a group of three students that turned into Lizard-men had surrounded Yukari Sendo.

"So what's the idea again?" One of the Lizard-men asked.

"You dipshit, Boss-san here's going to rape this witch and then leave her for dead in this forest! We're just here to hold her down while the boss sticks his Mara up her ass!" Another one said.

"Enough talking, you shit-brained idiots! If we take too much time the demons will no doubt get here and kill all of us before I can fuck Sendo-chan in the ass! I know that those Shiki-Oujis are supposed to protect us, but the demons here like to use Fire attacks." the third Lizard-man called Boss-san said.

At that point, three of the Shiki-Oujis burst into flames as they got hit by a Maragidyne fired by a Surt that Naoki had summoned as the Demi-Fiend himself used an Iron Claw attack that sliced a Lizard-man in half. A Loa that Naoki summoned earlier then used a Tetraja on him as Tsukune arrived. At once a Shiki-Ouji tried to use Hamaon on Tsukune, but the word 'VOID' appeared over the human's head. It was at that point that the Kodama that Yukari had befriended appeared and blew one of the remaining Lizard-men away with a Zan spell. The two remaining Shiki-Ouji and Boss-san decided that it was no longer possible to rape Yukari Sendo and they ran away.

* * *

**A/N: Yep, Tsukune is immune to Expel attacks. Unfortunately for Moka, she didn't join the fight to help Yukari because Miss Akashiya is weak to Expel. Then again, so is Kurumu. Naoki also hacked his Magatama this time.**

Naoki-'s Magatama in this chapter: Gaea

Gaea Rage

Iron Claw

Avenge

Deathbound

Endure

War Cry

Taunt

Dekaja

Immune to Physical, Resist Death and Force.


End file.
